Telephone system



C. L. GOODRUM.

TELEPHONE SYSTEM.

APPLlcATxoN HLED APR,24!1917.

Patented Apr. 20, 1920.

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CHARLES L. GOGDRUM, 0F NEW YORK, N. Y., ASSIGNOR T@ VESTERN ELECTRIC COMPANY, INCORPORATED, OE' NEW YORK, N. Y., A CORPRATION OF NEW YORK.

TELEPHONE SYSTEM.

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Specification of Letters atent. Patgnted Apr, 1920,

Application filed April 24, 1917. Serial No. 164,224.

To all whom t may conce-rn.'

Be it known that I, CHARLES, L. Gooi)- RUM, a citizen of the United States, residing at New York, in the county of New York and State of 'New York, have invented certain new and useful improvements in rlelephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone systems and more particularly to automatic telephone systems of the step-by-step type.

ln systems of this character it has been customary to employ combinations of fast and slow relays to control the setting and releasing movements of the switches employed therein. A

ln the present invention it is proposed to eliminate the slow relays formerly employed and to perform their functions by the stepping relays and magnets. These relays and magnets in certain of their operations are rendered mechanically slow and in other operations they are 'quick to operate.

The figure of the drawing diagrammatically represents a portion of a telephone system employing theV present invention. Only so much of the system has been disclosed as is necessary for a clear understanding of the invention.

The line finder and selector switches of any preferred form may be employed.

It is believed that the operation of the systeni 1will be best understood by establishing a connection from a calling to a called subscriber. ll'h en the subscriber' whose sub-station apparatus is at .EL removes his receiver from the switchliook, the brushes 100,101 and 1 02 are operated in the ell-known manner to engage the terminals`103, 104- and 105 of the calling line. With the brushes of the finder switch engaging the terminals of the calling line a circuit is completed for energizing the stepping relay of the first selector. The energizing circuit for this relay may be traced from ground, left-hand winding of the relay 106, side-switch wiper 107 in its first position, finder brush 101, terminal 104, substation apparatus A, terminal 103, finder brush 100, side-switch wiper 108 in its first position, right-hand winding of stepping relay 106, to grounded battery. The Yrelay 106 attracts its armature, which causes the roller 109 to be forced up the incline track 110. As soon as the roller 109 is forced from its normal position spring 111 engages Contact 112 to close a break point in the operating circuit of the primary. magnet 113. Then now the subscriber operates his dial to transmit impulses corresponding to the first digit of the desired number, the stepping relay 106 vibrates its armature and the right-hand armature in vibrating prevents the roller 109 from being restored to its ncrmal position. This armature also completes a circuit for the primary stepping magnet each time relay 106 is denergized from ground, back contact and armature of relay 106, spring 111, contact 112, winding of the primary stepping magnet 113, to grounded battery. stepping magnet attracts its armature the roller 114 is forced up the track 115 to cause the spring 116 to disengage the contact 117.

At the close of the directed movement of the first selector switch the primary stel ping magnet 113 retracts its armature for a relatively long interval, thereby permitting the `roller y114 to be restored to its normal position. In 'this position spring 116 engages the contact 117, thereby closing an energizing circuit for the escape magnet 118, which may be traced from grounded battery, winding of the escape magnet 118,

side-switch wiper 119 in its first position,

primary off-normal contact 120. which is closed after the first movement of the switch, contact 117, spring 116, armature and back contact of release magnet 121, to ground. The escape magnet is energized and moves the side switch into its second position.

In the second position of the side switch the stepping relay 106 remains energized and completes an operating circuit for the secondary stepping magnet 122, which circuit is established from grounded battery, winding, armature and back contact of relay 122, side-switch wiper 12S in its second position, left-hand front contact and armature of relay 106, to ground. The stepping magnet 122 interrupts its operating circuit to advance the brushes 124, 125 and 126 over the terminals of the trunks in the selected group. When the test brush 126 encounters ground at test terminal 127, which condition indicates that the trunk is idle, the escape magnet 118 is energized over a circuit which may be traced from grounded battery, winding of the escape magnet 118, conductor 128` side-switch wiper 129 in its second position, test brush 126, terminal 127,

As soon as the primary conductor 130, contact 131, spring 132, back contact and armature of relay 133, to ground. The escape magnet 118 is energized and moves the switch wipers into their third position.

With side-switch wipers 107 and 108 in their third position an energizing circuit is completed for the stepping relay 133, from ground, left-hand winding of relay 133, conductor 134, terminal 135, selector brush 124, side-switch wiper 108 in its third position, brush 100, terminal 103 of the calling line, substation apparatus A, terminl 104, the brush 101, side-switch wiper 107 in its third position, selector brush 125, terminal 136, trunk conductor 137, right-hand winding of stepping relay 133, to grounded battery. The relay 133 attracts its armature, thereby forcing the roller 138 up the incline track 139. When now the callingsubscriber operates his dial to transmit impulses corresponding tothe tens digit of the desired number the relay 133 vibrates its armature, which prevents the roller 138 from being restored toA normal and also completes a circuit eacli time relay 133 is denergized from ground, armature and back Contact of relay 133, spring 132, contact 140, conductor 141, outer lefthand armature and back contact of relay 142, side-switch wiper 143 in its first position, the winding of the primary stepping magnet 144, to grounded battery.

In response to the impulses from the calling dial the primary stepping magnet 144 advances the brushes 145, 146, and 147 of the connector switch to select the desired lgroup of lines in which the calling line ter- Y position, spring 151, contact 150, to ground.

'lhe side switch 'employed in the connector circuits is of that type ,which moves its wipers only on the denergization of the eS- cape magnet. 'At the closeof the first directive movement of the connector switch the magnet 144 retracts its armature and the roller 148 in returning to its normal position forces the spring 151 out of engagement with the contact 150. The escape magnet thereupon denergizes and moves the sideswitch wipers into their second position.

When the calling subscriber operates his l dial to. transmit impulses corresponding to `the units digit of the. desired number the stepping relay 133 vibrates its armature.

n operating circuit is thereby completed forthe secondaryV stepping magnet`14, which extends from grounded battery, winding of this magnetside-switch wiper 143 in its second position, outer left-hand contact and armature of relay 142, conductor 141, contact 140, spring 132, back Vcontact and armature of stepping relay 133, to ground. The stepping magnet 154 advances the brushes 145, 146 and 147 over the terminals of the selected group of lines. At the first energization of the secondary stepping magnet 154 it attracted its armature and thus caused the roller 155 to be forced up the incline track 156, to permit spring 157 to engage the contact 158. An energizing circuit is thereby completed for the escape magnet 152 which circuit ext-ends from groundedbattery, winding of magnet 152, side-switch wiper 153 in its second position, Contact 158, springV 157 to ground. At the close ofthe units series of impulses, the secondary magnet 154 has its energizing circuit interrupted at the back contact and armature of stepping relay 133. The stepping magnet 154 is thereby caused to re- `tract its armature and the roller 155 forces the spring 157 out of engagement with the contact 158. This interrupts the energizing circuit of the escape magnet, causing it to move the side switch into its third position.

ln this position the escape magnet 152 is energized over a circuit established from grounded battery, winding of escape magnet 152, side-switch wiper 153 in its third position, contact and armature of ringing trip relay 160 to ground. The escape magnet 152 attracts its armature and completes a circuit for the application of ringing current to the desired line. This circuit may be traced from ground, ringing currentV generator 161, winding of the ringing trip relay 160, armature'and front contact of escape magnet 152, side-switch wiper 162 in its third position, connector brush 146, terminal 163, substation apparatus B, terminal 164, connector brush 145, side-switch wiper 165 in its V,third position, to ground. The ringing trip relay160 is marginal and does not attract its armature until the ,called subscriber removes his receiver from the switchhook. At this time the relay 160 does attract its armature to cause the deenergization of the escape,V magnet 152. The escape magnet then moves the side-switch wipers into their fourth or talking position.

If, however, the desired line is busy, this condition will be indicated by the presence of ground on the test terminal 159, as a re-V 0nd position for a relatively long period, at the same time that the armature 'of the stepping magnet is retracted, a circuit is completed from grounded battery, right-hand winding of relay 142, resistance 168, offnormal contact 169, side-switch wiper 170 in its second position, contact 171, spring 157 to ground. The relay 142 is provided with a copper jacket of the well-known structure, which not only renders the relay 142 slow to release, but also renders it sluggish in attracting its armatures. The relay 142, because of this construction and by 'reason of the resistance 168, does not attract its armatures until the escape magnet 152 has had an opportunity to move the side-switch wipers into their third position, provided the desiredline is idle.

Y In case the desired line is busy, the relay 142 attracts its armatures and completes a locking circuit for itself from grounded battery through the left-hand winding of the relay 142, its inner armature and front contact, off-normal contact'172 to ground. When the relay 142 attracted its right-hand armature, a busy tone device, generally designated by the reference numeral 173, transmits a busy tone to the calling substation A to inform the subscriber that the desired line is busy.

At the termination of the conversation, when the calling subscriber replaces his receiver on the switchhook, the line relay 133, which has been maintained energized during conversation, retracts its armature and thereby completes an energizing circuit for the release magnet 174, which circuit may be traced from ground, armature and back contact of relay 133, spring 132, Contact 131, off-normal contact 175, winding of release magnet 174 to grounded battery. The release magnet 174 completes a locking circuit for itself which is maintained until the connector switch has been restored to. normal. This circuit is established from grounded battery, winding of magnet 174, ofi-normal contact 175, front contact and armature of magnet 174 to ground. A circuit in parallel with the circuit just described is completed over conductor 130, test terminal 127, test brush 126, side-switch wiper 129, off-normal contact 176, winding of release magnet 121, to grounded battery, to cause the restoration of the selector switch to its normal position. The release magnet 121 attracts its armature and also completes a locking circuit for itself from grounded battery, winding of release magnet 121,01f-normal contact 17 6, front contact and armature of release magnet 121, to ground.

What is claimed is:

1. A switch controlling system, a stepping relay having two sets of contacts, one set of contacts being responsive to each actuation of said relay,'the other set of contacts being responsive to a series of actuations of said relay, a switch, a magnet for operating said switch, a circuit for said operating magnet completed through said contacts, said magnet having a set of contacts arranged to be closed during the actuation of said magnet, a circuit controlling switch, a magnet therefor, and a circuit for said last Amentioned magnet completed at the contacts of said operating magnet.

2. Ina switch controlling system, a step- A ping relay having two sets of contacts, one

set of contacts being responsive to each actuation of said relay, the other set of contacts being responsive to a series of actuations of said relay, a switch, a magnet for operating said switch, a circuit Jfor said operating magnet completed serially through said contacts, said magnet having a set of contacts arranged to be held operated 'during the actuation ofv said magnet, a circuit controlling switch, a magnet therefor, and a circuit for said last mentioned magnet completed at the contacts of said operating magnet.

3. In a telephone system, an incoming line, a plurality of outgoing lines,fa switch for interconnecting said incoming line with any of said outgoing lines, a stepping relay provided with a plurality of contacts,

' certain of said contacts being arranged to be operated during momentary actuations of said relay, others of said contacts being arranged to be operated at the end of a series of actuations of said relay, a primary stepping magnet and a secondary stepping magnet, operating circuits for said magnets completed serially through said contacts, said primary and said secondary magnet having contacts arranged to be operated during the actuation of said magnets, a circuit controlling switch, a magnet therefor, and a circuit for said last mentioned magnet successively completed at the contacts of said primary and said secondary magnets.

4. In a telephone system, 'an incoming line, a plurality of outgoing lines, an automatic switch for interconnecting said incoming line with any of said outgoing lines, a line relay responsive to current impulses transmitted over said incoming line, said relay being provided with contacts responsive to each current impulse transmitted to said line relay, other contacts at said relay arranged to be held actuated during a series of impulses, a single armature at said relay for actuating all of said contacts, a motor magnet for advancing said switch, and an operating circuit for said magnet completed serially through the contacts of said line relay.

5. In a telephone system, an incoming line, a plurality of outgoing lines, an automatic switch for interconnecting said incoming line with any of said outgoing lines,

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a line relay controlled by impulses over said incoming line, said relay being provided with contacts responsive to each current impulse transmitted to said line relay, other contacts at said relay arranged to be held actuated during a series of impulses, a single armature at said relay for actuating all of said contacts, primary and secondary motor magnets for successively advancing said switch, and operating circuits for said magnets serially completed through the Vcontacts of said line relay.

(i. In a telephone system, an incoming line, a.plurality of outgoing lines, an automatic switch for interconnecting said incoming line with any of said outgoing lines, a line relay associated with said switch and controlled over said incoming line, said line relay being. provided with a plurality of sets of contacts :arranged to be actuated in different time'intervals, an armature at said Y switch, a stepping magnet for said switch,

a circuit controlling switch, an operating magnet therefor, a circuit for said operating magnet, contacts in said circuit, means'for transmitting. a series otimpulses to said ystepping magnet, an armature for said stepping-magnet, and means controlled by said armature for closing said contacts upon the first impulse of a series and opening said contacts only uponv the termination of the series of impulses.

9. In a telephoneV system, an automatic switch, a stepping magnet for said switch, an auxiliary switch, an operating magnet therefor, a circuit for said operating magnet, means for transmitting impulses to said stepping magnet, an armature for said stepping magnet, and contacts controlled directly by said armature for closing said circuit on the iirst impulse of a series to said stepping magnet and Aopening said circuit only at the termination of a series Vof impulses.

10. An automaticswitch, a stepping magnet for said switch, an armature for said stepping magnet, contacts controlled directly by said armature, said armature actuating said contacts upon the first energization of said magnet and permitting the reverse actuation of said contacts only upon the termination of a series of impulses to said magnet. Y' y 11,'In a telephone system, an automatic switch, a motor magnet for advancing said switch, a test circuit for said switch, contacts in said circuit, an armature for said stepping magnet directly controlling said contacts and operating on the initial energization of said magnet to open said test circuit and to close said test circuit only upon the termination of a series of impulses to said magnet.

12. In a telephone system, a switch, a stepping magnet therefor, an armature for said magnet, a set of normally open contacts and a set of normally closed contacts controlled directly by said armature, said armature operating to open the normally closed contacts and close'the normally open contacts upon the first impulse to said stepping magnet and permitting the contacts to assume their original condition only upon the termination of a seriesof contacts.

In witness whereof, I hereuntoV subscribe my name this 19th day of April, A. D. 1917.

oHARLns L. GoonnUM. 

